To explore the molecular mechanisms underlying 5hmC loss in bladder cancer, we also measured the expression of 5hmC-related enzymes (TET1, TET2, TET3, IDH1, IDH2, and L2HGDH) and vitamin C transporters (SVCT1 and SVCT2) by RT-qPCR and found that the expression of TET2, L2HGDH, and vitamin C transporters (SVCT1 and SVCT2) were relatively decreased in all bladder cancer cell lines (Fig. 3b). Here, IDH1 is linked to urinary bladder cancer.